Types I and III parotid collagen variations and serum biochemical parameters in obese rats exposed to monosodium glutamate / Variaciones de colágeno parotídeo tipos I y III y parámetros bioquímicos séricos en ratas obesas expuestas a glutamato monosódico

SUMMARY: The objective of this study was to describe the effects of monosodium glutamate on the collagen of the parotid gland in an obesity model. 18 newborn male Sprague Dawley rats were used (first control group; second group of MSG1: 4 mg/g of monosodium glutamate weight, 5 doses, and third group of MSG2: 4 mg/g of monosodium glutamate, 5 doses, maintained for 8 and 16 weeks respectively). The content and type of collagen were analyzed, in addition to the levels of cholesterol, glucose, triglycerides and uric acid. Monosodium glutamate produced an increase in the obesity rates of the MSG2 group, in addition to an increase in blood cholesterol, glucose and uric acid levels compared to the control group. Type III collagen in the MSG2 group showed a statistically significant increase. Monosodium glutamate induced obesity, in addition to an increase in type III collagen fibers.

RESUMEN: El objetivo de este estudio fue describir los efectos del glutamato monosódico sobre el colágeno de la glándula parótida en un modelo de obesidad. Se utilizaron 18 ratas Sprague Dawley machos recién nacidas (primer grupo control; segundo grupo MSG1: 4 mg/g de peso de glutamato monosódico, 5 dosis, y tercer grupo MSG2: 4 mg/g de glutamato monosódico, 5 dosis, mantenidas durante 8 y 16 semanas respectivamente). Se analizó el contenido y el tipo de colágeno, además de los niveles de colesterol, glucosa, triglicéridos y ácido úrico. El glutamato monosódico produjo un aumento en las tasas de obesidad del grupo MSG2, además de un aumento en los niveles de colesterol en sangre, glucosa y ácido úrico en comparación con el grupo control. El colágeno tipo III en el grupo MSG2 mostró un aumento estadísticamente significativo. La obesidad inducida por glutamato monosódico, además de un aumento en las fibras de colágeno tipo III.

Enhancement of cellular activity in hyperglycemic mice dermal wounds dressed with chitosan-alginate membranes

The use of specially designed wound dressings could be an important alternative to facilitate the healing process of wounds in the hyperglycemic state. Biocompatible dressings combining chitosan and alginate can speed up wound healing by modulating the inflammatory phase, stimulating fibroblast proliferation, and aiding in remodeling phases. However, this biomaterial has not yet been explored in chronic and acute lesions of diabetic patients. The aim of this study was to evaluate the effect of topical treatment with a chitosan-alginate membrane on acute skin wounds of hyperglycemic mice. Diabetes mellitus was induced by streptozotocin (60 mg · kg-1 · day-1 for 5 days, intraperitoneally) and the cutaneous wound was performed by removing the epidermis using a surgical punch. The results showed that after 10 days of treatment the chitosan and alginate membrane (CAM) group exhibited better organization of collagen fibers. High concentrations of interleukin (IL)-1α, IL-1β, granulocyte colony-stimulating factor (G-CSF), and tumor necrosis factor-alpha (TNF-α) were detected in the first and second days of treatment. G-CSF and TNF-α level decreased after 5 days, as well as the concentrations of TNF-α and IL-10 compared with the control group (CG). In this study, the inflammatory phase of cutaneous lesions of hyperglycemic mice was modulated by the use of CAM, mostly regarding the cytokines IL-1α, IL-1β, TNF-α, G-CSF, and IL-10, resulting in better collagen III deposition. However, further studies are needed to better understand the healing stages associated with CAM use.

Effect of growth hormone (GH) and resistance training on the collagen properties of femoral bone tissue / Efecto de la hormona de crecimiento (HC) y el entrenamiento de fuerza en las propiedades colágenas del tejido óseo femoral

The indiscriminate use of anabolic steroids in gyms has been growing in a generalized way, among which, the most common is growth hormone (GH). In the short term GH may potentiate muscle growth, especially when taken in combination with resistance training. However, the effects of this hormone are not yet fully understood in the literature, especially in relation to collagen properties. The objective of this study was to evaluate the effect of the application of growth hormone (GH) and resistance training (RT) on the collagen properties of femoral bone tissue using Raman Spectroscopy. In this study 40 male rats were randomly distributed into four groups (n=10): control (C), control and GH application (GH), resistance training (T), and resistance training and GH application (GHT). The training consisted of four series of 10 water jumps, performed three times a week, with an overload corresponding to 50 % of body weight and duration of four weeks. GH was applied at a dosage of 0.2 IU/Kg (0.067 mg/kg) to each animal, three times a week, every other day. The animals were euthanized and the right femurs were collected for analysis of bone structure. Raman spectroscopy (RS) was used to observe the following compounds from their respective bands: type I collagen (662 cm-1), amide III (1243 cm-1), proteins including type I collagen (1278 cm-1), woven collagen (1322 cm-1), association of collagen, phospholipids, nucleic acid, and phosphate (1330 cm-1), and collagen and protein deformation (1448 cm-1). The results demonstrated an increase in the collagen properties in all analyzed variables, however, the T group presented a statistically significant difference (p<0.05). It is possible to conclude that isolated physical training was shown to be more efficient than when combined with the application of GH to increase the collagen properties of the femoral bone tissue.

El uso indiscriminado de anabolizantes en los gimnasios ha aumentado de forma generalizada, entre éstos la hormona de crecimiento (HC) es una de las más utilizadas, y a corto plazo puede potencializar el crecimiento muscular, principalmente cuando es realizado en combinación con el entrenamiento de fuerza. Sin embargo, los efectos de esta hormona aún no están totalmente esclarecidos en la literatura, especialmente en relación a las propiedades colágenas. El objetivo del estudio fue evaluar el efecto de la aplicación del HC y entrenamiento de fuerza (E) en las propiedades colágenas del tejido óseo femoral a partir de la utilización de la espectroscopía Raman. Se usaron 40 ratas Wistar distribuidos en cuatro grupos (n=10): control (C), control y aplicación del HC (HCC), entrenamiento de fuerza (E) y entrenamiento de fuerza y aplicación del HC (THC). El entrenamiento fue compuesto por cuatro series de 10 saltos acuáticos, realizados tres veces por semana, con sobrecarga correspondiente a 50 % del peso corporal y duración de cuatro semanas. El HC fue aplicado en una dosificación de 0,2 UI/Kg (0,067 mg/kg) en cada animal, tres veces por semana, en días no consecutivos. Los animales fueran eutanasiados y se retiró el fémur derecho para realización del análisis de la estructura ósea. La espectroscopía Raman (ER) fue utilizada para observar los siguientes compuestos a partir de las respectivas bandas: colágeno tipo I (662 cm-1), amida III (1243 cm1), proteínas, incluido colágeno tipo I (1278 cm-1), colágeno retorcido (1322 cm-1), asociación de colágeno, fosfolípidos, ácidos nucleicos y fosfato (1330 cm-1), deformación de colágeno y proteína (1448 cm-1). Hubo aumento en las propiedades colágenas en todas las variables analizadas, sin embargo, solamente el grupo E demostró una diferencia estadísticamente significativa (p<0,05). En conclusión, para el aumento de las propiedades colágenas del tejido óseo femoral, el entrenamiento físico aislado es más eficiente que el entrenamiento combinado con el uso de HC.

Accelerated collagen cross-linking in the management of advanced Acanthamoeba keratitis / Cross-linking acelerado de colágeno no controle da ceratite por Acanthamoeba avançada

ABSTRACT Purpose: To report our initial experience in the treatment of Acanthamoeba keratitis with accelerated corneal collagen cross-linking. Methods: Retrospective chart review of patients diagnosed with Acanthamoeba keratitis with progressive corneal melting who were treated with accelerated collagen cross-linking. Results: A total of 6 eyes (5 patients) were reviewed. All the patients received adjuvant therapy with moxifloxacin and chlorhexidine. In 4 cases, the ulcer healed with a mean interval to epithelialization of 108.8 days (range 59-217). In 2 eyes, there was a persistent neurotrophic ulcer. The melting was not progressive in any case, nor did any eye required emergency penetrating keratoplasy. Conclusion: This study suggests a beneficial effect of accelerated collagen cross-linking in cases of Acanthamoeba keratitis with corneal melting. Thus, collagen cross-linking may be considered as adjuvant treatment for Acanthamoeba keratitis.

RESUMO Objetivo: Relatar nossa experiência inicial no tra tamento da ceratite por Acanthamoeba com reticulação acelerada de colágeno corneano. Métodos: Revisão retrospectiva de prontuários de pacientes diagnosticados com ceratite por Acanthamoeba, com deformação progressiva da córnea, tratados com reticulação acelerada de colágeno. Resultados: Seis olhos (5 pacientes) foram incluídos. Todos os pacientes receberam terapia adjuvante com moxifloxacina e clorexidina. Em 4 casos, a úlcera cicatrizou com uma média de epitelização de 108,8 dias (amplitude de 59-217 dias). Em dois pacientes, a úlcera apresentou um comportamento neurotrófico. A deformação não foi progressiva em nenhum dos pacientes e nenhum dos olhos exigiu ceratoplastia penetrante de emergência. Conclusão: Este estudo sugeriu um efeito benéfico da reticulação acelerada de colágeno em casos de ceratite por Acanthamoeba infecciosa com deformação corneal. A reticulação de colágeno parece ser uma alternativa coadjuvante possível para casos de ceratite por Acanthamoeba.

Effect of risperidone on proliferation and apoptosis of MC3T3-E1 cells

This aim of this study was to assess the molecular mechanism of osteoporosis in schizophrenia patients with risperidone use. Here, we investigated the effects of risperidone on cellular proliferation and apoptosis of a preosteoblast cell line, MC3T3-E1. Cell viability and apoptotic rate of MC3T3-E1 were detected by cell counting kit-8 and flow cytometry at a serial dose of risperidone and at different time points, respectively. Bone transformation relevant gene serum osteocalcin (BGP), collagen 1, tumor necrosis factor-α (TNF-α), osteoprotegerin (OPG), and receptor activator of nuclear factor-κB ligand (RANKL) mRNA levels were determined by real-time PCR (qPCR). Their protein expression patterns were evaluated using western blot. The results revealed that risperidone dramatically inhibited MC3T3-E1 cell proliferation in a dose-dependent manner. It also significantly induced MC3T3-E1 cell apoptosis. TNF-α gene and protein levels were greatly enhanced after risperidone treatment. In contrast, BGP, collagen 1, OPG, and RANKL gene and protein levels were markedly downregulated. Our study indicated that risperidone suppressed MC3T3-E1 cell proliferation and induced apoptosis. It also regulated BGP gene and protein expression.

Effects of tadalafil to prevent injury on corpus cavernosum after vascular or nervous peri-prostatic bundle injury. Experimental model in rats

Abstract Purpose: To evaluate the effects of tadalafil (TD) in preventing histological alterations of the corpus cavernosum caused by isolated lesions of cavernous nerve (ILCN) and artery (ILCA) in rats. Methods: Fifty male Wistar rats were randomly assigned in five groups: G1: control; G2: bilateral ILCN; G3: bilateral ILCA; G4: ILCN+TD; G5: ILCA+TD. The cavernous bodies were submitted to histomorphometry, immunohistochemistry and biochemical analysis. Results: Nerve density was significantly higher in G2 and G4 compared to control (22.62±2.84 and 19.53±3.47 vs. 15.72±1.82; respectively, p<0.05). Smooth muscle density was significantly lower in G2 and G3 in comparison to G1 (12.87±1.90 and 18.93±1.51 vs. 21.78±1.81, respectively; p<0.05). A significant decrease in the sinusoidal lumen area was observed in G2 compared to controls (5.01±1.62 vs. 9.88±3.66, respectively; p<0.05) and the blood vessel density was increased in G2 and G3 (29.32±4.13 e 20.80±2.47 vs. 10.13±2.71, p<0.05). Collagen density was higher in G3 compared to G1 (93.76±15.81 vs. 64.59±19.25; p<0.05). Conclusions: Histomorphometric alterations caused by ILCN were more intense than those produced by vascular injury, but the collagen analyses showed more fibrosis in animals with ILCA. TD was effective in preventing the majority of the alterations induced by the periprostatic bundle injury.

Local treatment with ascorbic acid accelerates recovery of post-sutured Achilles tendon in male Wistar rats

Tendon rupture is a very frequent accident involving average people and high-performance athletes. Clinical studies describe tendon recovery as a painful and slow process involving different biochemical and histological events. Ascorbic acid (AA) is a potent antioxidant as well as an important cofactor for collagen synthesis. In the current study, we evaluated if local treatment with AA is able to promote tendon repair in tenotomized rats. Animals were submitted to Achilles tendon rupture followed by surgical suture. Control and AA groups received in loco injection of saline solution (0.9% NaCl) and 30 mM AA, respectively. Histological and functional recovery of Achilles tendon tissue was evaluated at 7, 14, and 21 days post-surgery. Hematoxylin/eosin staining and collagen fluorescence analysis showed intense disarrangement of tendon tissue in the saline group. Tenotomized animals also showed hypercellularity in tendon tissue compared with non-tenotomized animals. The Achilles functional index (AFI) showed a significant decrease of tendon functionality in tenotomized animals at 7, 14, and 21 days post-surgery. AA accelerated tissue organization and the recovery of function of the Achilles tendons. The beneficial effect of AA treatment was also observed in the organization of the collagen network. Data presented in the current work showed that in loco treatment with AA accelerated the recovery of injured Achilles tendon post-surgery.

Efeitos da arginina na reparação cicatricial da parede abdominal em ratos Wistar / Effects of arginine on abdominal wall wound healing in Wistar rats

RESUMO Objetivo: avaliar os efeitos da arginina na cicatrização da parede abdominal de ratos Wistar. Métodos: vinte ratos Wistar foram submetidos à laparotomia e separados em dois grupos (arginina e controle), que receberam tratamento diário por via intraperitoneal com arginina (300mg/kg/dia) e solução tampão fosfato em dose equivalente ao peso, respectivamente, durante cinco dias. No sétimo dia pós-operatório, coletaram-se amostras de sangue e da cicatriz da parede abdominal de ambos os grupos. Avaliaram-se o nível sérico de nitratos e nitritos, a evolução cicatricial pelas dosagens de hidroxiprolina tecidual, formação de tecido de granulação, determinação da porcentagem de colágeno maduro e imaturo, densidade de miofibroblastos e angiogênese. Empregaram-se os testes de ANOVA e t de Student com p=0,05 para as comparações entre os grupos. Resultados: não ocorreram diferenças significantes entre os grupos estudados para dosagens de nitratos e nitritos (p=0,9903), hidroxiprolina tecidual (p=0,1315) e densidade de miofibroblastos (p=0,0511). O grupo arginina apresentou maior densidade microvascular (p=0,0008), maior porcentagem de colágeno tipo I (p=0,0064) e melhora na formação do tecido de granulação, com melhores índices de proliferação angiofibroblástica (p=0,0007) e re-epitelização das bordas (p=0,0074). Conclusão: na avaliação cicatricial da parede abdominal de ratos Wistar sob tratamento com arginina, não houve alteração do nível sérico de nitratos e nitritos, da deposição de colágeno total e da densidade de miofibroblastos. Verificaram-se aumento da maturação de colágeno do tipo I, da densidade microvascular e melhora na formação do tecido de granulação cicatricial pelas melhores re-epitelização de bordas e proliferação angiofibroblástica.

ABSTRACT Objective: to evaluate the effects of arginine on abdominal wall healing in rats. Methods: we submitted 20 Wistar rats to laparotomy and divided them into two groups, arginine and control, which then received, respectively, daily intraperitoneal treatment with arginine (300mg/kg/day) and weight-equivalent phosphate buffered solution, during five days. On the seventh postoperative day, we collected blood and scar wall samples from both groups. We evaluated serum nitrate and nitrite levels, wound evolution by tissue hydroxyproline dosages, granulation tissue formation, percentage of mature and immature collagen, myofibroblast density and angiogenesis. We used the ANOVA and the Student's t tests with p=0.05 for comparisons between groups. Results: there were no significant differences between the groups studied for nitrate and nitrite (p=0.9903), tissue hydroxyproline (p=0.1315) and myofibroblast density (p=0.0511). The arginine group presented higher microvascular density (p=0.0008), higher percentage of type I collagen (p=0.0064) and improved granulation tissue formation, with better angiofibroblastic proliferation rates (p=0.0007) and wound edge reepithelization (p=0.0074). Conclusion: in the abdominal wall healing evaluation of Wistar rats under arginine treatment, there was no change in serum nitrate and nitrite levels, total collagen deposition and myofibroblast density. There was an increase in type I collagen maturation, microvascular density and improvement in scar granulation tissue formation by better edge reepithelization and angiofibroblastic proliferation.

Effect of acute administration of nicotine and ethanol on tooth movement in rats

Abstract The aim of this study was to evaluate the effect of acute administration of nicotine and ethanol on tooth movement in rats. Two hundred rats were divided into eight groups: S: saline; N: nicotine; E: ethanol; NE: nicotine and ethanol; SM: saline with tooth movement; NM: nicotine with tooth movement; EM: ethanol with tooth movement; and NEM: nicotine and ethanol with tooth movement. All the solutions were applied for 32, 44, or 58 days, according to the subgroup. Orthodontic movement (25 cN) was initiated 30 days after solution administration in the groups with tooth movement. The rats were euthanized 2, 14, or 28 days after initiation of tooth movement. Tooth sections were stained using picrosirius and tartrate-resistant acid phosphatase (TRAP). The data were compared by ANOVA using Tukey's HSD and Games-Howell. On day 28 of tooth movement, the NEM group had a lower percentage of type I collagen compared to the SM group (p = 0.0448), and the S group had a higher number of osteoclasts/μm2 compared to the N group (p = 0.0405). Nicotine and ethanol did not affect the tooth movement rate, regardless of induction of orthodontic movement. Nicotine influenced the number of osteoclasts by decreasing their quantity when dental movement was not induced. When nicotine was associated with ethanol, it interfered in the maturation of collagen fibers during orthodontic movement.

Bonding efficiency and durability: current possibilities

Abstract Bonding plays a major role in dentistry nowadays. Dental adhesives are used in association with composites to solve many restorative issues. However, the wide variety of bonding agents currently available makes it difficult for clinicians to choose the best alternative in terms of material and technique, especially when different clinical situations are considered. Moreover, although bonding agents allow for a more conservative restorative approach, achieving a durable adhesive interface remains a matter of concern, and this mainly due to degradation of the bonding complex in the challenging oral environment. This review aims to present strategies that are being used or those still in development which may help to prevent degradation. It is fundamental that professionals are aware of these strategies to counteract degradation as much as possible. None of them are efficient to completely solve this problem, but they certainly represent reasonable alternatives to increase the lifetime of adhesive restorations.

Effects of the essential oil of Alpinia zerumbet (Pers.) B.L. Burtt & R.M. Sm. on healing and tissue repair after partial Achilles tenotomy in rats

Abstract Purpose: To investigate the cellular response to injury, analyzing histopathologic changes associated with increased cellularity, degeneration and disorganization of collagen fibers. Methods: Thirty wistar rats were divided in two groups after partial Achilles tenotomy: the right hind paw were treated with the essential oil of Alpinia zerumbet (EOAz), diluted to 33% (0.3 mL kg-1), and the left hind paw received sunflower oil for 3, 14, 30 and 90 days. Statistical significance was determined using a Chi-square and Pearson Correlation qualitative variables test. Moreover, Mann-Whitney U-test test for comparison between different groups of the same cell, one-way ANOVA, and Tukey's test of quantitative measurement. Results: A decrease hyperemia (p < 0.001) was observed in the acute phase of inflammatory cell number (p < 0.001), whereas sub-acute phase was marked by significant correlation with macrophages in fibroblasts (r = 0.17, p = 0.03), with probable induction a dense and modeled tissue. At chronic phase, it was found an increase in the number of fibroblasts and a higher percentage of type I collagen fibers (78%) compared with control collagen fibers (55%). Conclusion: Oil of Alpinia zerumbet stimulated the process of maturation, organization and tissue repair which gave it greater resistance.

Experimental burns: Comparison between silver sulfadiazine and photobiomodulation / Queimadura experimental: comparativo entre sulfadiazina de prata e fotobiomodulação

Summary Objective: To analyze morphological characteristics and organization of the collagen fibers of third degree burns from scalding compared to laser therapy and silver sulfadiazine, the latter considered as the gold standard. Method: Were selected 12 animals (Rattus norvegicus) also divided into three groups (control group [CG] - untreated burns; sulfadiazine group [SG] - burns were treated with silver sulfadiazine at 1%; laser group [LG] - burns were treated with photobiomodulation). The scald burns were carried out by using PVC mold, and the material collected on the 14th day after burn was prepared for morphological and optical retardation analysis for evaluation of inflammatory infiltrates and collagen organization, respectively. Results: On the 14th day, the laser and sulfadiazine groups had mild inflammatory response, while the control group showed an intense inflammatory process, with statistical significance between laser and control groups, but not between sulfadiazine and control groups. Laser and sulfadiazine groups no longer had granulation tissue, opposite to what was seen in the control group. The presence of hair follicles and ulcer did not significantly differ between groups. The optical retardation of collagen fibers was higher in sulfadiazine group, followed by laser and control groups. As for systemic effect, we were able to identify it by simply analyzing the presence or absence of granulation tissue. Conclusion: Morphologically, the laser or silver sulfadiazine treatments were similar and both provided better organization of collagen fibers in relation to the untreated group. However, the sulfadiazine group modulated the deposition of collagen fibers more efficiently than the laser group.

Resumo Objetivo: Analisar características morfológicas e organização das fibras colágenas de queimaduras de terceiro grau provocadas por escaldo em relação à terapia com laser e àquela considerada padrão-ouro, a sulfadiazina de prata. Método: Foram selecionados 12 animais (Rattus norvegicus), divididos igualmente em três grupos (grupo controle [GC] - queimaduras não tratadas; grupo sulfadiazina [GS] - queimaduras tratadas com sulfadiazina de prata 1%; grupo laser [GL] - queimaduras tratadas com fotobiomodulação). As queimaduras foram realizadas por escaldo com a utilização de molde de PVC, e o material coletado no 14º dia pós-queimadura foi preparado para análise morfológica e de retardo óptico, para avaliação do infiltrado inflamatório e da organização do colágeno, respectivamente. Resultados: No 14º dia, os grupos laser e sulfadiazina apresentaram resposta inflamatória leve, enquanto o grupo controle apresentou processo inflamatório intenso, havendo significância estatística entre os grupos laser e controle, mas não entre os grupos sulfadiazina e controle. Enquanto os grupos laser e sulfadiazina não apresentavam mais tecido de granulação, o grupo controle ainda apresentava. A presença de folículo piloso e de úlcera não diferiu significantemente entre os grupos. O retardo óptico das fibras colágenas foi maior no grupo sulfadiazina, seguido dos grupos laser e controle. Apenas a análise da presença ou ausência de tecido de granulação permitiu identificar o efeito sistêmico. Conclusão: Morfologicamente, os tratamentos com laser ou sulfadiazina de prata foram similares e ambos proporcionaram maior organização das fibras colágenas em relação ao grupo não tratado. Entretanto, o grupo sulfadiazina modulou a deposição das fibras colágenas mais eficientemente que o grupo laser.

The influence of growth factors on skin wound healing in rats / A influência de fatores de crescimento na cicatrização de feridas cutâneas de ratas

ABSTRACT INTRODUCTION: Healing is a process that restores the physical integrity of body structures. It is a dynamic, complex, multicellular process that involves the extracellular matrix, cytokines, blood cells, and growth factors. Growth factors are proteins that activate and stimulate cell proliferation through the activation of angiogenesis, mitogenesis, and gene transcription, accelerating the healing process. OBJECTIVE: To assess the influence of growth factors on the healing process of wounds made on the backs of female rats compared to the control wound, through macro and microscopy. METHODS: This study used 45 female Wistar rats, in which three wounds were made on the back. The first was the control wound, the second received epithelial growth factor injection, and the third received a combination of factors. Macroscopic and microscopic assessments were performed on the third, seventh, and 15th days of the experiment. For microscopic analysis, hematoxylin-eosin staining was utilized to assess the inflammatory process; vimentin, for assessment of blood vessels and fibroblasts, and Sirius Red for collagen assessment. RESULTS: In the macroscopic assessment, the use of growth factors resulted in faster healing and decrease of granulation tissue on days seven and 15; (80.31% reduction in the control wound vs. 83.24% in the epithelial wound vs. 100% in the mixed wound). Utilizing microscopy, at the three stages of the experiment, there were no significant differences between the three wounds; however, when comparing the day of euthanization for each type of wound, there was a favorable outcome for epithelial and mixed wounds (between the third vs. 15th day, p < 0.001, and in the comparison of the seventh vs. 15th day; p = 0.002 and p = 0.001 for epithelial and mixed wounds, respectively) with a higher number of fibroblasts, angiogenesis, and collagen type I. CONCLUSION: The use of growth factors accelerates healing, stimulates greater angiogenic activity, and accelerates fibroplasia and collagen maturation.

Resumo Introdução: A cicatrização é um processo de restauração da integridade física das estruturas do corpo. É um processo dinâmico, complexo, multicelular que envolve matriz extracelular, citosinas, células sanguíneas e fatores de crescimento. Os fatores de crescimento são proteínas que estimulam e ativam a proliferação celular mediante a ativação da angiogênese, mitogênese, transcrição genética, acelerando o processo de cicatrização. Objetivo: Avaliar a influência dos fatores de crescimento no processo cicatricial de feridas realizadas no dorso de ratas em comparação com a ferida, controle através da macro e microscopia. Método: Foram utilizadas 45 ratas Wistar, submetidas à criação de três feridas no dorso. A primeira controle a segunda com injeção de fator de crescimento epitelial e a terceira com fator misto. As avaliações macroscópicas e microscópicas foram realizadas no 3º, no 7º e no 15º dia do experimento. Para análise microscópica, utilizou-se coloração de Hematoxilina-Eosina para avaliar o processo inflamatório; vimentina, para a avaliação dos vasos e fibroblastos, e Sirius Red, para avaliar o colágeno. Resultados: Na avaliação macroscópica, o uso de fatores de crescimento proporcionou cicatrização mais rápida e diminuição do tecido de granulação no 7º e 15º dia (80,31% de redução na ferida controle vs. 83,24% na ferida epitelial vs. 100% na ferida mista). Na microscopia, nos três momentos do experimento, não foram encontradas diferenças significativas entre as três feridas; entretanto, quando comparados os dias de morte em relação a cada tipo de ferida, observou-se resultado favorável para as feridas epiteliais e mistas (entre 3º × 15º dia apresentou p < 0,001 e na comparação entre 7º × 15º dias; p = 0,002 e p = 0,001 para as feridas epiteliais e mistas) com maior número de fibroblasto, angiogênese e colágeno tipo 1. Conclusão: A utilização de fatores de crescimento acelera a cicatrização, estimula maior atividade angiogênica, acelera a fibroplasia e maturação do colágeno.

Inflammatory response of human dental pulp to at-home and in-office tooth bleaching

ABSTRACT Tooth bleaching is a technique of choice to obtain a harmonious smile, but bleaching agents may damage the dental pulp. Objective: This study evaluated the inflammatory responses of human dental pulp after the use of two bleaching techniques. Material and Methods: Pulp samples were collected from human third molars extracted for orthodontic reasons and divided into three groups: control - no tooth bleaching (CG) (n=7); at-home bleaching with 15% carbamide peroxide (AH) (n = 10), and in-office bleaching with 38% hydrogen peroxide (IO) (n=12). Pulps were removed and stained with hematoxylin-eosin for microscopic analysis of inflammation intensity, collagen degradation, and pulp tissue organization. Immunohistochemistry was used to detect mast cells (tryptase+), blood vessels (CD31+), and macrophages (CD68+). Chi-square, Kruskal-Wallis, and Mann Whitney tests were used for statistical analysis. The level of significance was set at p<.05. Results: The inflammation intensity and the number of macrophages were significantly greater in IO than in AH and CG (p<0.05). The results of CD31+ (blood vessels per mm2) were similar in CG (61.39±20.03), AH (52.29±27.62), and IO (57.43±8.69) groups (p>0.05). No mast cells were found in the pulp samples analyzed. Conclusion: In-office bleaching with 38% hydrogen peroxide resulted in more intense inflammation, higher macrophages migration, and greater pulp damage then at-home bleaching with 15% carbamide peroxide, however, these bleaching techniques did not induce migration of mast cells and increased the number of blood vessels.

Histological response to platelet-rich plasma added to polypropylene mesh implemented in rabbits

ABSTRACT Introduction: The platelet-rich plasma (PRP) is part of a set of biotechnologies, providing some growth factors that promote repair of different tissues. The polypropylene meshes (PPM) are applied in the correction of abdominal defects, pelvic floor and urinary incontinence, however, they induce many significant complications, as a result of an inappropriate inflammatory response. Purpose: To investigate the changes caused by PRP associated with the implantation of PPM in the abdomen of female rabbits, in the production of collagen I and III and the inflammatory infiltrate (ININ). Materials and Methods: We performed implant meshes with and without PRP in adult rabbits (n=30) and euthanasia at 7, 30 and 90 days. Two plates were prepared from each animal and analyzed in five different fields. The ININ was evaluated by quantification of inflammatory cells using hematoxylin-eosin and the collagen by Sirius red method. The results were analyzed applying the Wilcoxon, Kruskal-Wallis, Junckheere and Friedmann tests. Results: There was a significant difference in the number of inflammatory cells between the groups with and without PRP (p=0.01) at 90 days. There was increased production of collagen I, III and total with the use of PRP, at seven days. Conclusion: The PPM coating with PRP was associated with increased ININ at the implant area, and an increasing trend during the process of tissue repair. The PPM coated with PRP was related to increased concentration of collagen I, collagen III and the concentration of total collagen increased after seven days of implantation.

TNF-alpha expression, evaluation of collagen, and TUNEL of Matricaria recutita L. extract and triamcinolone on oral ulcer in diabetic rats

ABSTRACT Diabetes mellitus (DM) is a disease associated with delayed wound healing of oral ulcers by increased expression of proinflammatory cytokines and cellular apoptosis. Objective to evaluate the influence of Tumor Necrosis Factor alpha (TNF-α) and apoptosis in rats with DM treated with chamomile extract or triamcinolone. Material and Methods Wistar male rats (210.0±4.2 g) were divided into five groups: negative control group (NCG) without diabetes; positive control group (PCG) with DM (alloxan, 45 mg/kg); and groups treated with chamomile extract (normoglycemic= NCG group and diabetic= DCG group) and with triamcinolone (TG). Traumatic ulcers were performed on all animals that received topical triamcinolone, chamomile extract or saline 12/12 hours for ten days. Results On days five and ten the animals were euthanized and the ulcers were analyzed by light microscopy, TUNEL assay, and immunohistochemically (TNF-α). The NCG (p=0.0062), PCG (p=0.0285), NCG (p=0.0041), and DCG (p<0.0001) groups were completely healed on the 10th day, however, there was no healing on the TG (p=0.5127) group. The TNF-α expression showed a significant reduction from the 5th to the 10th day in NCG (p=0.0266) and DCG (p=0.0062). In connective tissue, the TUNEL assay showed a significant reduction in the number of positive cells in NCG (p=0.0273) and CNG (p=0.0469) and in the epithelium only in CDG (p=0.0320). Conclusions Chamomile extract can optimize the healing of traumatic oral ulcers in diabetic rats through the reduction of apoptosis in the epithelium and TNF-α expression.

Tissue dissolution and modifications in dentin composition by different sodium hypochlorite concentrations

ABSTRACT Sodium hypochlorite (NaOCl) remains the most used irrigation solution during root canal preparation because of characteristics such as wide-spectrum antimicrobial activity and organic tissue dissolution capacity. However, these solutions can alter dentin composition and there is no consensus on the optimal concentration of NaOCl to be used. Objectives To determine the organic matter dissolution and changes in dentin chemical composition promoted by different concentrations of NaOCl over time. Material and Methods: Fragments of bovine muscle tissue were weighed before and after 5, 10, and 15 min of immersion in the groups (n=10): G1- 0.9% saline solution; G2- 1% NaOCl; G3- 2.5% NaOCl; and G4- 5% NaOCl. Bovine dentin fragments were subjected to the same irrigants and absorption spectra were collected by Attenuated Total Reflectance of Fourier Transform Infrared Spectroscopy (ATR-FTIR) before and after 0,5, 1, 2, 3, 5, 8, and 10 min of immersion in the solutions. The ratios of the amide III/phosphate and carbonate/phosphate absorption bands were determined. The tissue dissolution and carbonate/phosphate ratios were submitted to the two-way analysis of variance (ANOVA) with Tukey’s multiple-comparison test (α<0.05) and to the one-way analysis of variance with Tukey’s (α<0.05). The amide III/phosphate ratio was analyzed by Friedman test (α<0.05) and the Kruskal-Wallis test with Dunn’s post-hoc (α<0.05). Results The increase in NaOCl concentration and contact time intensified the dissolution of organic matter and dentin collagen with reduction in the amide III/phosphate ratio. Significant differences between all groups (p<0.05) were observed in the dissolution of organic matter at 10 min and in the amide III/phosphate ratio between the saline solution and 5% NaOCl at 5 min. The carbonate/phosphate ratio decreased significantly in G2, G3, and G4 after 0,5 min of immersion (p<0.05), but more alterations did not occur in the subsequent periods (p>0.05). Intergroup differences were not observed in this ratio (p>0.05). Conclusions The increase in the exposure time and in the concentration of NaOCl solution lead to an increase in the tissue dissolution and dentin collagen deproteination. Furthermore, some carbonate ions are removed from the dentin inorganic phase by the NaOCl.

Effects of platelet rich plasma on fascial healing in rats with fecal peritonitis

ABSTRACT PURPOSE : To evaluate the effects of platelet rich plasma (PRP) on the healing of fascia wherein peritonitis has been created. METHODS: Twenty eight Wistar Albino rats were divided into four groups. Only a primary fascial repair following laparotomy was performed on Group 1, a primary fascial repair performed and PRP treatment applied following laparotomy on Group 2, and a fecal peritonitis created following laparotomy and a primary fascial repair carried out on Group 3. A fecal peritonitis was created following laparotomy and primary fascial repair and PRP treatment on the fascia was carried out on Group 4. RESULTS: TNF-α was found to be significantly lower in the control group (Group 1). It was detected at the highest level in the group in which fecal peritonitis was created and PRP applied (Group 4). TGF-β was determined as being significantly higher only in Group 4. Histopathologically, the differences between the groups in terms of cell infiltration and collagen deposition were not found to be significant. CONCLUSION: When platelet rich plasma was given histologically and biochemicaly as wound healing parameters cellular infiltration, collagen accumulation, and tissue hydroxyiproline levels were not increased but neovascularization, fibroblast activation and TNF Alfa levels were increased and PRP accelerated wound healing.

Simvastatin and biphasic calcium phosphate affects bone formation in critical-sized rat calvarial defects

ABSTRACT PURPOSE: To investigate the effects of locally applied simvastatin plus biphasic calcium phosphate (BoneCeramic(r)) or collagen sponge on bone formation in critical-sized bone defects. METHODS: Thirty defects of 5mm in diameter were created bilaterally with a trephine bur in the calvariae of fifteen Wistar rats. The defects were divided into five groups: group 1 - control, no treatment; group 2 (BoneCeramic(r)); group 3 (BoneCeramic(r) + 0.1mg simvastatin); group 4 (collagen sponge); and group 5 (collagen sponge + 0.1mg simvastatin). After eight weeks the animals were euthanized and their calvariae were histologically processed. Hematoxylin and eosin-stained sections were subjected to histological and histomorphometrical analyses. The area of newly formed bone was calculated and compared between groups. RESULTS: The greater amount of a bone-like tissue was formed around the carrier in group 3 (BoneCeramic(r) + 0.1mg simvastatin) followed by group 2 (BoneCeramic(r)), and almost no bone was formed in the other groups. Group 3 was significantly different compared to group 2, and both groups were significantly different compared to the other groups. CONCLUSION: Simvastatin combined with BoneCeramic(r) induced significantly greater amounts of newly formed bone and has great potential for the healing of bone defects.

Effects of Growth Hormone on Cardiac Remodeling During Resistance Training in Rats / Efeitos do Hormônio do Crescimento na Remodelação Cardíaca Durante Treinamento Resistido em Ratos

Abstract Background: Although the beneficial effects of resistance training (RT) on the cardiovascular system are well established, few studies have investigated the effects of the chronic growth hormone (GH) administration on cardiac remodeling during an RT program. Objective: To evaluate the effects of GH on the morphological features of cardiac remodeling and Ca2+ transport gene expression in rats submitted to RT. Methods: Male Wistar rats were divided into 4 groups (n = 7 per group): control (CT), GH, RT and RT with GH (RTGH). The dose of GH was 0.2 IU/kg every other day for 30 days. The RT model used was the vertical jump in water (4 sets of 10 jumps, 3 bouts/wk) for 30 consecutive days. After the experimental period, the following variables were analyzed: final body weight (FBW), left ventricular weight (LVW), LVW/FBW ratio, cardiomyocyte cross-sectional area (CSA), collagen fraction, creatine kinase muscle-brain fraction (CK-MB) and gene expressions of SERCA2a, phospholamban (PLB) and ryanodine (RyR). Results: There was no significant (p > 0.05) difference among groups for FBW, LVW, LVW/FBW ratio, cardiomyocyte CSA, and SERCA2a, PLB and RyR gene expressions. The RT group showed a significant (p < 0.05) increase in collagen fraction compared to the other groups. Additionally, the trained groups (RT and RTGH) had greater CK-MB levels compared to the untrained groups (CT and GH). Conclusion: GH may attenuate the negative effects of RT on cardiac remodeling by counteracting the increased collagen synthesis, without affecting the gene expression that regulates cardiac Ca2+ transport.

Resumo Fundamento: Apesar de os efeitos benéficos do treinamento resistido (TR) sobre o sistema cardiovascular estarem bem estabelecidos, poucos estudos têm investigado os efeitos crônicos da administração de hormônio do crescimento (GH) sobre a remodelação cardíaca durante um programa de TR. Objetivo: avaliar os efeitos do GH sobre a remodelação cardíaca em suas características morfológicas e na expressão dos genes do trânsito de Ca2+ em ratos submetidos ao TR. Métodos: Ratos Wistar machos foram divididos em 4 grupos (n = 7 por grupo): controle (CT), GH, TR e TR com GH (TRGH). A dose de GH foi de 0,2 UI/kg, a cada dois dias, por 30 dias. O modelo de TR utilizado foi o salto vertical em água (4 séries de 10 saltos, 3 vezes/semana) durante 30 dias consecutivos. Após o período experimental, as seguintes variáveis foram analisadas: peso corporal final (PCF), peso do ventrículo esquerdo (PVE), razão PVE/PCF, área seccional de cardiomiócitos (ASC), fração de colágeno, creatina quinase fração músculo-cérebro (CK-MB) e expressão gênica de SERCA2a, fosfolambam (PLB) e rianodina (RyR). Resultados: Não houve diferença significativa (p > 0,05) entre os grupos para PCF, PVE, razão PVE/PCF, ASC, e expressão gênica de SERCA2a, PLB e RyR. O grupo TR mostrou um significativo aumento (p < 0,05) da fração de colágeno em comparação aos outros. Além disso, os grupos treinados (TR e TRGH) apresentaram maiores níveis de CK-MB em comparação aos não treinados (CT e GH). Conclusão: Esses resultados indicam que o GH pode atenuar os efeitos negativos do TR na remodelação cardíaca por contrabalançar o aumento da síntese de colágeno, sem afetar a expressão de genes que regulam o trânsito de Ca2+ cardíaco.